Abstract: In order to improve the operational capability and performance of aircraft, IMA core system shall be applied in mission organization, functional integration and system management in future aircraft. Based on the studying of IMA system and airborne computing, a Distributed Modular Integrated Avionics (DMIA) architecture model is proposed which takes the Time-triggered FC(TTFC) network as unified airborne network. Combining with analysis of IMA2G requirement and core composition characteristics, The key technologies and applications solutions in IMA core system including mulit-core processing, Time-triggered FC network, system management and reconfiguration are also studied, and the system is verified by prototype system development and tests. The results show that the DMIA architecture model and key technology performance meet the system requirements, and can be taken as a reference for development of IMA system in the future aircraft.